Searchlight



E. PEARSE SEARCHLIGHT April 26, 1932.

Filed Oct. v6. 1930 3 Sheets-Sheet jail! lNV ENTO R {am/N0 PEnRsE ATl N EY April 26, 1932? V E, PEAR E 1,855,867

SEARCHLIGHT Filed Oct. 6, 1930 5 SheetsSheet 2 INVENTCR gamma I EA/78E April 26, 1932; E PEARSE 1,855,867

SEARCHLIGHT Filed Oct. 6, 1950 3 Sheets-Sheet I5 INVENTOR foMu/vp PE/IRSE Patented Apr. 26 1932 UNITED STATES PATENT OFF IC E rese ilcrs Application filed October 6, 1930 Serial No. 486 62, and in ,Qregt Britain pctober 14, QQQS.

5 to leave a relatively dark zone straight ahead as required particularly by vessels travelling by night through the buez Canal.

The advantages of electric arcsas the source of light in searchlights are generally known particularly the advantage due to the smallness of the light source. Owing, however, to the relatively great expense of arc lamp mechanism and its need of skilled attention, incandescent light is sometimes used as the light source in projectors and the disadvantage due to the unavoidably great size of the light source is overcome or minimized by so-cal-led stray light rings in the form of short cylinders or rings mounted concentrically with respect to the beam axis.

The chief object of the present invention is to render the use of an incandescent light sourcepractica'ble in searc'hlights ofthe Suez Canal type andwith this object in view the invention consists broadly dividing the stray light rings and providing means whereby lateral deflection oi the half-rings takes place correspondingly with lateral deflection of the halves of the spl-it-beam. Clearly, however, although the invention is particularly applicable to projectors using incandescent light it is also applicable to are :lamp projectors.

For simplicity and uniformity of operation, the half-rings and half-mirrors may be interconnected in pairs so that a single manipulation causes actuation of both pairs, for which purpose each half-ring may be connected to the corresponding half-mirror by an convenient form of gearing or linkage or ot er form of mechanical transmission. In one simple embodiment of the invention the half-rings are mounted upon a vertical hinge-pin common to all of them, whilst each half-ring or set of half-rings is connected by a link to the adjusting mechanism of the split mirror.

The stray-light rings may be of the usual form or of any other form suited to the purpose in view.

The diverging of the two halves of the rings in accordance with the present invention not only deals ellectively'with the stray light but serves to present an obstructionto the light which ordinarily streams directly forward from an incandescent lamp. M

In order that the invention be clearly understood and readily carried into seat the same will now be described more fully with reference to the accompanying drawings which illustrate one embodiment of the invention and in which i Figures 1 and? are-two diagrammatic pl-an views of a searchlight with paraboloid mirror, Figure 1 showing the beam un=split whilst Figure 2 sho-wsitsplit.

Figure 3 is end view of one half of the set of stray light rings seen-in plan in Figures '1 and 2.

Figures 4 5 are views similar to Figures "1 and 2 respectively of a sear-ch:light having a mirror which is p anabolic yentical section and elliptical in horizontal seotion.

Figure 6 is an end View of one half of the set of stray light rings seen in plan in Figures 4 and '5. l

Figure 7 is a front elevation of an incandescent lamp projector constructed and adapted to operate in accordance with the present invention.

Figure 8 is a longitudinal section and F, igure 9 is ahprizontalsection. it

Referring first to 1 to 3 it is seen that light from the source l strikes the split mirror'Q and is thereby-directed forwards as aicy-l'inglrical {beam Figure l and as a convergi-ngbeam in Figure 4. The central portion of the beal-n in each case passes through the concentric stray light rings 3, According to Figure 52 the beam is split into two diverging siibstantia lly semi-cylin'drical beams and the two halves ofgt'he split rings are anade 'to diverge correspondingly from a common vertical hingepinl i" at the rear end oftherings ,3. According ito d lignrebthe beam istsplitinto two:half beamscrossing one anotherlandzthe two halves ofitherings :3 are correspondingly displaced angular-1y about a common vertical hinge pine .atathe front end of the rings. It will understood that instead of hinging the half rings at their front or rear ends as shown in Figures 5 and 2 respectively, any other convenient means for enabling the halves to be moved divergingly may be employed.

Referring now to the construction shown in Figures 7 8 and 9 the drum casing 5 is shown tiltably mounted in the yoke 6 surmounting the pedestal 7. At the front of the drum are mounted the split rings 3 and at the rear is mounted the split mirror 2 whilst between the rings and the mirror and at the focus of the latter is mounted the incandescent lamp 1 as light source.

The split mirror 2 is mounted in a split carrier ring 8 the halves of which are rockably secured to the drum by vertical hinge pins 9, 9, so that each half mirror with its half ring carrier can be moved angularly around the vertical axis of the hinge pins.

The mechanism shown for moving the halves of the carrier ring 8 comprises a handle 1O pivoted to rock in a horizontal plane about apivot pin 11 carried by abracket 12 secured to and projecting outwardly from the centre of the back plate of the drum. This handle 10 is connected to one half of the carrier 8 by means of a horizontal link 11 and curved vertical arm 12* and is connected to the other half of the carrier by means of a horizontal link 13 and a similar curved vertical arm. The points of connection of the horizontal links 11 and 13 with the handle 10 are on opposite sides of its pivot pin 11 and the points of connectionof the respective arms 12 with the respective carrier halves are on opposite sides of the vertical hinge pins 9. Hence a rocking motion of the handle 10 will cause the halves of the carrier 8 to swing towards one another as shown in dotted lines in Figure 9 or away from one another.

The twohalves of the stray light rings 3, 3, are secured as to one half to a vertical rod 4: and as to the other half to sleeve members 4 surrounding the rod, the said rod and sleeve members constituting the entire hinge pin for the rings. The rod 4 is secured to its half of the split rings by two lateral arms or cranks 14 (Fig. 7 and the sleeves 4? are secured to their half of the split rings by lateral arms or cranks 15 (Fig. 7).

The rocking of the halves of the mirror in unison with the halves of the rings is efiected by horizontally extending bars 16 and 17.

It will be understood that by rocking the handle 10 to right or to left the mirror halves will be made to converge or diverge and that the halves of the stray light rings will be simultaneously rocked to correspond, the dotted positions of the ring halves in Fig. 9 corresponding with the dotted positions of the respective mirror halves. Obviously, however, the rocking of the mirror halves in unison with the ring halves can be efiected by various other forms of mechanism and that the linkages above described are only one embodiment of the necessary means.

Each D-shaped assembly of half rings 3 has a solid vertical wall or boundary plate 3* (Figs. 3 and 6) and it is to be noted that when the halves are angularly separated as shown either in Figures 2 or 5 the divergent vertical plates present a central baflle or obstacle of appreciable size to light travelling forwardly direct from the lamp and thereby perform the useful function of preventing such direct light from becoming troublesome to approaching vessels. 7

What I claim is 1. A searchlight of the type having a split mirror forming two hinged halves and stray light rings, characterized by the fact that the stray light rings are also split forming two hinged halves so as to be capable of movement to correspond with the movements of the mirror halves.

2. A searchlight as claimed in claim 1, in which the halves of the split mirror are mechanically connected to the respective halves of the stray light rings so as to move therewith.

3. A searchlight comprising a mirror formed in two halves swingable about a diametrical hinge, stray light rings also formed in two halves swingable about a diametrical hinge, means connecting each half-mirror to its respective half-ring so that they move together, and means for turning the connected pairs about their hinges.

4. A searchlight as claimed in claim 3 in which the means provided to move the mirror halves and ring halves are controlled from a common operating handle.

5. A searchlight as claimed in claim 3 in which the respective halves of the stray light rings are provided with vertical boundary plates to offer an effective balfie or obstacle to the travel of beam rays directly forward when the beam is split.

In testimony whereof I have signed my name to this specification.

EDMUND PEARSE. 

